Which of the Following Statements Is Incorrect Concerning Influenza Testing

Which of the following statements is incorrect concerning influenza testing?

A) The specimen for testing influenza is usually a nasal swab or nasal wash.
B) The influenza test strips usually test for influenza A, B, and C.
C) Presence of a blue test line in A and a pink control line is a valid positive test for influenza type A.
D) Presence of a blue test line in B and a pink control line is a valid positive test for influenza type B.